Even now, 13 years later, Brian Lewis, a former Navy petty officer third class, has difficulty describing how he was raped at knifepoint by a superior officer.

Lewis, stocky in a Harley-Davidson T-shirt, with hair as close-cropped as a newly enlisted sailor’s, pauses for long moments and frequently squeezes his eyes shut as he tells the story.

Lewis, now 34, was stationed aboard the submarine tender USS Frank Cable out of Guam. A more senior petty officer invited Lewis to dinner, took him to a beach at the naval station, and assaulted him.

But the attack was, in some ways, not the worst of Lewis’ ordeal. A friend who found him afterward insisted that Lewis report the incident, which he did.

Then, Lewis said, “a few days later a very senior member of the chain of command informed me that I was not to pursue anything further” with criminal investigators.

“It was a very huge disappointment to know that the chain of command was going to throw me aside because my assailant was a senior person,” Lewis said.

Lewis was sent for mental health counseling, where a doctor cleared him to return to the ship, saying “it would do good to be exposed to the environment again.”

That was not a good idea. “I was constantly scared. I was afraid for my life,” Lewis said. “There’s only so many places to run inside a 600-foot-long ship.” His assailant remained on board, hard to avoid in such a contained environment.

Lewis was transferred to San Diego, where his Navy psychiatrist eventually accused Lewis of lying about the attack. He was diagnosed with borderline personality disorder and given a less-than-honorable general discharge.

The Department of Veterans Affairs has since been treating Lewis for the post-traumatic stress disorder that the Navy psychiatrist had declared a fiction. He has suffered from depression and attempted suicide several times. “Sexual assault just really takes a rip at the core of a human being, male or female,” he said.

Lewis’ experience sounds both recognizable and unfamiliar. His description of a system that ignored claims and blamed victims is sadly common. Military commanders assert that times have changed; Lewis begs to differ.

But his is also the hidden face of the problem of sexual assault in the military. Women are more likely than men to be the victims in such cases. But in sheer numbers, more military men than women are targets of assault, mostly by other men.

“One of the big differences is the sense of public shame and scorn,” said Lewis. “There’s this perception that men aren’t to be violated this way and it makes it very difficult for men to come forward and break that social taboo.”

In March, Lewis became the first male victim to testify before Congress about military sexual assault; he used his testimony to thank his partner. “Being homosexual has nothing to do with sexual assault,” Lewis said. “Sexual assault is … a crime about power and control. It’s not a crime based on sexual orientation.”

But Lewis’ sexuality, at a time when don’t ask, don’t tell was the law, made his situation even more difficult. “I was put in a terrible position,” he said. “I was told that this is homosexual contact.”

He has earned a bachelor’s degree, is on the brink of a master’s in paralegal studies, and is applying to law school, intending to advocate for veterans.

“I don’t get much of a choice,” Lewis said of his decision to go public. “If I don’t talk about it, if men in general don’t talk about it, we’re not going to get the help that we need.”

Washington Post columnist Ruth Marcus may be contacted at ruthmarcus@washpost.com.